1. Technical Field
The subject matter described herein generally relates to the field of semiconductor chip manufacturing and includes security measures throughout the semiconductor chip lifecycle and also for secure boot flow.
2. Background Information
In semiconductor chip manufacturing, semiconductor chips may be formed together as a wafer and tested while part of the wafer. Then a wafer may be diced into individual chips/devices where they undergo further testing followed by provisioning before being incorporated into products. In some instances, it may be useful to re-provision chip devices for alternative applications during or after manufacturing.
One-time programmable non-volatile storage technology has become widely used in semiconductor chip manufacturing. Examples of such one-time programmable non-volatile storage technology include fuses such as e-Fuses, anti-fuses, or laser fuses. Such fuses may be used to change the configuration of semiconductor chips after they are manufactured as well as to tune performance. Fuses may also be used for chip ID storage and cryptographic key storage.
E-Fuse technology includes one-time programmable non-volatile storage technology in which e-Fuse bit(s) may be set to 1 only once while the un-programmed bit(s) may have zero values. An available e-Fuse technology uses electrically programmable PMOS gate oxide anti-fuses in which a read operation requires only the core IC power supply, whereas programming may be performed using an external power supply.
E-Fuses may be arranged as independent fuse macros, in which each macro may have a capacity, for example, in the range of 64-bit to 1-kbit in 64 bit increments.